Internal combustion engine



1934. L. LAUBENDER 1,970,382

INTERNAL COMBUSTION ENGINE Filed Aug. 50, 1930 2 sheets sheet 1 I INVENTOR- 10 BY I rm RN 5% Aug. 14, 1934. L. LAUB'ENDER- INTERNAL COMBUSTION ENGINE Filed Aug. 30, 1930 I/III/IIIII/I 2 Sheets-Sheet 2 UNITED STATES PATENT OFFICE INTERNAL comsos'rron ENGINE Ludwig Laubender, Winterthur, Switzerland, as- I signer to the firm ofSulzer Freres Societe Anonyme, Winterthur, Switzerland Application August 30, 1939, Serial No. 479,049 In Switzerland September 5, 1929 Claims. (Cl. 123-79) This invention relates to internal combustion Figure 5 shows in vertical section an alternaengines of the four-stroke Diesel type provided tive form of engine cylinder.

with a common valve serving to control both the Fig. 6 is a longitudinal section through a workadmission of air and the discharge of the proding cylinder in two positions of controlled slots. ucts of combustion. Fig. 7 is a section through line VIV'I of Fig. 6. do In such engines if the common valve is closed In'the construction shown in Figures 1 and 2 exactly at the end of the suction stroke the cylthe cylinder 1 which is secured to the crank case inder has not received its full charge of air. on 2 is provided with a common valve 3- which conthe other hand if the valve remains open during trols both the admission of air through the openld the first portion of the compression stroke, aling 4 and the discharge of the products of com- 65 though more air will be admitted the maximum bustion through the opening 5. In addition the charge of air in the working chamber will be cylinder wall is provided with ports 6 which (see reduced by the travel of the piston during the Figure 2) open tangentially into the working compression stroke. Further, for certain, for exchamber. ample, mechanical reasons sudden opening or The piston 9 is shown at the beginning of its 74 closing of the valves has to be avoided so that compre sion stroke in Fi u e v lv 3 in the valves must be made to close in a gradual closed. When the piston begins to cover the ports manner which adversely affects the charge. 6 as s w y d d lines the w r n chamber Although ports, unlike openings controlled by '7 is completely charged with air. Towards the valves, can be made to give a quick cut off, hithend of the compression stroke fuel introduced 75; erto it has not been'possible in engines of the through an injection device 8 is automatically above type to charge the cylinder fully with ignited and the pressure thus generated is transair and it is the object of this invention to promitted by the piston 9 and connecting rod 10 to vide an engine which will be free from this disthe crank 11 in the usual manner. g5 advantage. Thetalve 3 opens before the ports 6 are uncov- 39 According to this invention additional air ports ered so that the products of combustion escape independent of the common valve are provided through the op n A r Pressure q li through which air can be supplied to the cylinder tion has taken place fresh a is admitted t u at the beginning of or after the closing of the e p s 6 into the Working Chamber d during 30 common valve so as to compensate for the gradual the exhaust stroke this air is expelled from the g5 closing of the common valve by air admitted cylinder with the products of combustion. through ports which can be suddenly closed. With the suction stroke admission of fresh air Preferably this air is admitted through ports through the opening 4 begins and Wh h piston h h r uncovered wh th piston i t t occupies the position shown in dotted lines and $5 and of t cylinder remote from t common begins to uncover the ports 6 the valve 3 is closed alve and some of these ports may be provided SO the cylinder receives Charge Of all with one or more automatically acting valves. thrqughfihese and maximumfiuamity Alternatively some of the ports may be valve-conof W111 be i to F F- trolled so that air can be admitted through some In the construction Shown m Flgure 3 m addl' all ports whilst others, also valve controlled can be mm the ports 6 further ports 15 are provided 95 at a higher level. A valve 16 actuated by a cam gig: for the dlscharge of products of combus' 19 on the cam shaft through rod 17 and lever Three constructions according to this invention 18 g g wortkmg chamber of the cylinder to e cu o from he air pipe 20. A second cam zfipi ii ait gz'gzifigg figg gg ggg fi g fi i 21 on the cam shaft controls the common closing 1w h valve 3 throu h r 22 bl Figure 1 shows in Vertical sectional elevation lever 24 pivotefi at 23. The i ad m zfid i nt m i ti a four-stroke Dlesel engine adapted for airless cylinder through the ports 15 is preferably at a, or solld Injection of 11 higher pressure than the other air so that after m Fi 2 1s a cross-semen on the lme IIII of being charged with air through the opening 105 l e l and when the ports 6 have been closed supers Figure 3 ShOWS a modified Constructlon 1n Ve charging can take place through the ports 15. tical section, Figure 3 shows the piston 9 nearly at the end Figure 4 is a cross-section on the line IV-IV of the expansion stroke just before the lower or Figure 3, and dead centre. The valve 3 is open, the waste gases 11a therefore can escape through. the opening 5 and the pressure within the cylinder is lowered so that air can enter the cylinder through the ports 6. The valve 16 is still closed so that no air can enter the cylinder through the ports although they are uncovered by the piston 9. During the upstroke of the piston, any combustion gases remaining in the chamber will be swept out through the opening 5. When the suction stroke begins the cylinder is filled with air which is first admitted through the opening 4,

then through the ports 6 and finally, after the valve 16 has been opened by the valve gear, through the ports 15. The common valve is preferably closed before the piston uncovers the ports 6 in its outward stroke.

Towards the end of the compression stroke fuel is injected through anozzle 8 into the compressed charge which is ignited owing to the high temperature which the fuel has reached through compression, the expansion or working stroke being thus produced. Towards the end of this working stroke the valve 3 is opened so that the waste gases will pass through the opening 5 either into the open or into an exhaust passage whereupon the cycle already described will be repeated.

Figure 4 shows the cam 19 by which the valve 16 is operated and alsothe second cam 21 which actuates the common valve 3, both these cams being mounted on the cam shaft 25. Instead of a positively operated valve any automatically acting valve may be employed. The ports 6 and 15 are arranged tangentially to the cylinder so that air is admitted through each of them in the same direction. Some of the ports may be inclined at an angle to the radial direction. If desired the ports may be provided with separate control devices such as non-return valves some of which may be used only to admit air whilst others only allow the exhaust gases .to escape,-

thus enabling the engine to be worked even if the common valve 3 becomes'jammed. Some of the ports may be directed towards the cylinder head or common valve and others may extend in a plane at right angles to the axis of the cylinder.

In the construction shown in Figure 5 the piston 9 reciprocates within a cylinder 1 which is made in one piece and is provided with a valve 3 which controls both the admission of air and the discharge of waste gases.- The surface of the valve 3 directed towards the air inlet opening 4 is constantly cooled by the air whilst the surface which closes the opening in the upper wall of the cylinder is located close to the ignition zone and therefore remains at'a. high temperature.

This results in the valve being deformed so that after a time it does not seat itself properly and it is the object of the present invention to obviate this drawback.

According to this invention separate openings 30 are formed in the engine cylinder through which cooling air is directed againstthe inner surface of the valve, the openings 30 being inclined towards this valve surface. To prevent the products of combustion from entering the pipe 20 through which this cooling air is admitted a valve 31 is provided which can be positively operated if desired.

In the drawings the piston 9 is shown in its lowest dead centre position in which the valve 3 is already closed although air can still enter the cylinder through additional ports 15 and 30. This additional air cools thevalve 3 and is compressed during the compression stroke. Fuel in- 'the ports 15 and 30 so that the valve which troduced into the cylinder at the end of the compression stroke through the nozzle 8 is ignited owing to the high temperature due to the compression of the charge, and ignition causes the piston to descend thus transmitting the force acting uponit through the connecting rod 10 to the crank (not shown) in the usual manner.

W'hen the pressure in the-cylinder is sufficiently low cooling air for the valve 3 will enter through has been raised to a. high temperature at the moment of ignition, will be thoroughly cooled. 1 Consequently during the exhaust stroke not only the hot gases. but also fresh air .come into contact with this valve and during the suction stroke of the piston the valve remains open and will again be thoroughly cooled at the end of the suction stroke by the air entering through the ports 15 and 30. As these ports are open for a relatively long period theheating of the incoming air is prevented.

In Fig. 6 the air line 20 is connected by means of pipe 26 with the pressure vessel 27 to which the air is supplied through the nipple 28 from a compressor (not shown). Whilst the slots 15 are disposed at an angle relatively to the diameter, the slots 29 (Fig. 7) extend radially. The slots 29 are provided with a flow-intercepting element 30 which latter enables the combustion gases to make their exit and which is driven by means of lever 31, rod 32,v andlever 33 from the cam disc 34.

I claim:

1. In a four-stroke Diesel internal combustion engine having a cylinder, a piston therein, a common valve controlling both the admission of air and the discharge of the products of combustion, the combination with said valve of additional, quickly-closing, piston-controlled air-admission ports, independent of the common valve, for supplying air to the cylinder near the time of the closing of the common valve, some of said additional ports being provided with a control valve and being uncovered by the piston be- .fore the other ports in the cylinder.

2. In a four-stroke Diesel-internal combustion engine having a cylinder, a piston therein, a conunon valve for controlling both the admission of air and the discharge of the products of combustion, the combination with said valve of additional, quickly-closing, piston-controlled airadmission ports, independent of the common valve, for supplying air to the cylinder near the time of the closing ofthe common valve, some of said ports being provided with a valve permitting the admission of air, the others having a valve which permits the exhaust gases to escape. 3. In a four-stroke Diesel internal combustion engine having a cylinder, a piston therein, a common valve controlling both the admission of air and the discharge of the products of combustion, the combination with said valve of additional, quickly-closin piston-controlled air-admission ports, independent of the common valve, for supplying air to the cylinder near the time'of'the opening of the common valve, some of said ports "being provided with a valve permitting the adquickly-closing, piston-controlled air-admissions ports, independent of the commonvalve, tor supplying air to the cylinder near the time of the closing of the common valve, the additional air being introduced into the cylinder, to cool the common valve, through independent openings in the cylinder wall, said openings being directed towards that face of the common valve which is in contact with the charge at the moment of ignition.

5. In a four-stroke Diesel internalcombustion engine having a cylinder, a piston therein, a common valve controlling both the admission of air and the discharge of the products of combustion, 

